<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<link rel="stylesheet" href="./css/index.css" />
<title>记事本</title>
</head>
<body>

<!-- 主体区域 -->
<section id="app">
  <!-- 输入框 -->
  <header class="header">
    <h1>小黑记事本</h1>
    <input placeholder="请输入任务" class="new-todo" v-model="todoName" />
    <button class="add"  @click="add">添加任务</button>
  </header>
  <!-- 列表区域 -->
  <section class="main">
    <ul class="todo-list">
      <li class="todo"  v-for="(itme,index) in list">
        <div class="view">
          <span class="index">{{index+1}}.</span> <label>{{itme.todo}}</label>
          <button class="destroy" @click='del(itme.id)'></button>
        </div>
      </li>
    </ul>
  </section>
  <!-- 统计和清空 -->
  <footer class="footer" v-show="list.length>0">
    <!-- 统计 -->
    <span class="todo-count">合 计:<strong> {{list.length}} </strong></span>
    <!-- 清空 -->
    <button class="clear-completed" @click="clear">
      清空任务
    </button>
  </footer>
</section>

<!-- 底部 -->
<script src="./vue.js"></script>
<script>

  const app = new Vue({
    el: '#app',
    data: {
      todoName: '',
      list: [
          { id: 1, todo: '吃饭饭' },
          { id: 2, todo: '睡觉觉' },
          { id: 3, todo: '喝水水' }
        ]
    },
    methods: {
        // 删除
        del(id) {
          this.list = this.list.filter(item => item.id !== id)
        },
        // 底部
        clear(){
          this.list=[]  
        },
      // 添加
      add() {
          if (this.todoName.trim() === '') {
            alert('请您输入待办事项')
            return
          }
          this.list.unshift({
            id: +new Date(),
            todo: this.todoName
          })
          this.todoName = ''
        },

      }

  })
 
</script>
</body>
</html>
